Biomedical subjects

S Anton

Publications and source records attributed to S Anton.

At least 19 recordsLinked to original sources

PubMed2002

Plant odour processing in the antennal lobe of male and female grapevine moths, Lobesia botrana (Lepidoptera: Tortricidae).

Moths of Lobesia botrana (Lepidoptera: Tortricidae) are confronted with different volatiles emitted from the host plant during the different seasons. To test the hypothesis of plasticity of central plant odour processing in moths of different generations in the future, we first investigated the responses of antennal lobe (AL) interneurons of laboratory-reared virgin and mated males and females. We used intracellular recording and staining techniques while stimulating the antenna with a range of host and non-host plant odours. The AL structure of L. botrana is similar to that found in other Lepidoptera species studied. The most frequent physiological responses for all types of moths were obtained with (E)-2-hexenal, and with thujyl alcohol and beta-thujone, components of tansy, a behaviourally attractive non-host plant. Some broadly responding neurons were capable of distinguishing between different compounds through different response patterns (excitation/inhibition) and/or different dose-response characteristics. Response characteristics (response spectra, threshold and specificity) of neurons were similar, independent of sex or mating status of the moths. Significant differences between the groups were, however, found in the proportion of responding neurons for a few tested components.

Journal Article↗

PubMed2001

Transient post-mating inhibition of behavioural and central nervous responses to sex pheromone in an insect.

Mating is costly for both male and female insects and should therefore only occur if it is likely to be successful. Within one scotophase, which is the dark period of the light cycle, male moths can only produce one single spermatophore, which is transferred to the female during mating. Remating within the same scotophase would thus be unsuccessful. We tested the hypothesis that newly mated males of the moth Agrotis ipsilon have developed an energy-saving strategy based on the transient inhibition of their sexual behaviour, thus avoiding unsuccessful remating. Agrotis ipsilon males do not copulate more than once during the same scotophase. Moreover, newly mated males do not respond behaviourally to the female sex pheromone although electroantennograms showed that their peripheral olfactory system is fully functional. However, intracellular recordings of antennal lobe neurons showed that the sensitivity for the synthetic sex pheromone blend decreased as compared with that of unmated males. Both the sexual behaviour and the sensitivity of the antennal lobe neurons were restored when tested during the next scotophase. Our results show a fast, transient neuronal plasticity that 'switches off' the olfactory system, which could prevent males from mating unsuccessfully.

Animals↗

PubMed2001

Olfactory protocerebral pathways processing sex pheromone and plant odor information in the male moth Agrotis segetum.

We investigated protocerebral processing of behaviorally relevant signals in the turnip moth, Agrotis segetum. Single neurons were studied both physiologically and morphologically using intracellular recording techniques. In moth pheromone communication systems, the presence of the complete, female-produced pheromone blend is necessary for male attraction. We predicted that more protocerebral neurons, compared with AL, would display blend interactions. However, only a few protocerebral neurons responded differently to the blend than could be deduced from the response to single components. The majority of the pheromone-sensitive protocerebral neurons identified in this study responded to the major pheromone component. In coding time, most AL neurons can follow a 5-Hz odor stimulus, whereas most protocerebral neurons failed at higher frequencies than 1 Hz. The majority of neurons that responded to the odorants tested innervated one or both of the protocerebral lateral accessory lobes. If only one of these was innervated, then the innervation always displayed a varicose appearance, suggesting a presynaptic function. Thus, information seems to be transferred from other protocerebral areas to the lateral accessory lobes. Into these, descending neurons sent smooth, postsynaptic branches. A majority of the neurons innervating the superior medial protocerebrum were found to display single-component specificity. Few additional correlations between odor specificity and structural characteristics were apparent.

Animals↗

PubMed2001

The antennal lobe of orthoptera - anatomy and evolution.

The first odor-processing neuropils of insects comprise glomeruli, islets of neuropil, that are supplied by olfactory receptor neurons and give rise to efferent axons to higher brain centers. Glomeruli size and organization varies in a taxon-specific manner across the Insecta, suggesting possible correlates between their organization and chemosensory behaviors in different insect groups. Comparative studies of antennal lobe glomeruli within the Orthoptera have been used to infer how the various taxon-specific arrangements of odorant-processing structures (glomeruli) might have evolved. The cellular arrangements in glomeruli have been surveyed using anterograde filling and Golgi impregnation of antennal receptor neurons projecting to the antennal lobe in Stenopelmatidae, Tettigoniidae, Gryllidae, Tetrigidae and Acrididae. These taxa, which represent the two sub-orders of Orthoptera, reveal a high correlation between the neural architecture of the glomeruli and structures within the glomeruli. Using a recent molecular phylogeny of the Orthoptera we have mapped the occurrence of glomerular characteristics to infer the evolution of antennal lobe structures in orthopterans. The functional implications of these results are discussed.

Animals↗

PubMed2001

Juvenile-hormone-mediated plasticity of aggregation behaviour and olfactory processing in adult desert locusts.

In desert locusts Schistocerca gregaria, aggregation behaviour is elicited by aggregation pheromones. In this study, we show that the behavioural response to the major and most potent adult aggregation pheromone component, phenylacetonitrile, is age- and juvenile-hormone-dependent. Furthermore, we show that juvenile hormone influences the responsiveness of olfactory interneurons in the antennal lobe to aggregation pheromone, whereas the responsiveness of antennal receptor neurons is not changed. Old locusts and locusts injected with juvenile hormone, in contrast to young locusts and locusts deprived of juvenile hormone through allatectomy, i.e. after surgical removal of the gland producing this hormone, do not display any aggregation behaviour, as indicated by long-term behavioural observations. The lack of positive olfactory-guided behaviour coincides with an impairment of the central olfactory system, which displays a lower number of neurons responding to aggregation pheromone. Indirect and direct actions of juvenile hormone at different levels of the central nervous system may thus contribute to the regulation and modulation of behavioural responsiveness in the locust.

Acetonitriles↗

PubMed2000

Central processing of sex pheromone stimuli is differentially regulated by juvenile hormone in a male moth.

In the male moth, Agrotis ipsilon, the neuronal basis for juvenile hormone (JH)-linked modulation of sex pheromone responsiveness was investigated following stimulation of the antenna with i) an extract of female pheromone gland, ii) the synthetic pheromone blends from A. ipsilon and a closely related species, A. segetum, and iii) single components of the A. ipsilon blend. Response characteristics of olfactory interneurons were studied in the antennal lobe (AL) at different ages and with manipulated JH levels using intracellular recording techniques. Blend-specific, generalist and component-specific neurons were identified and described according to their response pattern. The proportion of low threshold AL interneurons increased significantly with age for all stimuli tested. Changes were, however, less pronounced for the minor single components. The proportion of low threshold AL interneurons in allatectomized (JH-deprived) mature males was significantly lower for all stimuli than in intact mature males. A large proportion of low threshold AL interneurons responding to the pheromone blends, but not as pronounced for single pheromone components, could be restored/induced by injecting JH either into JH-deprived mature males or into young immature males. The specificity for the species-specific blend compared to the A. segetum blend increased with age and JH injections.

Journal Article↗

PubMed2000

Function and morphology of the antennal lobe: new developments.

The antennal lobe of insects has emerged as an excellent model for olfactory processing in the CNS. In the present review we compile data from areas where substantial progress has been made during recent years: structure-function relationships within the glomerular array, integration and blend specificity, time coding and the effects of neuroactive substances and hormones on antennal lobe processing.

Animals↗

PubMed1999

Effect of juvenile hormone on the central nervous processing of sex pheromone in an insect.

Behavioral sex pheromone responsiveness in the male moth Agrotis ipsilon was previously shown to be controlled by juvenile hormone (JH). However, this morphogenetic hormone did not change the sensitivity of antennae to sex pheromones. To analyze the possible involvement of JH in the central integration of the female-produced sex pheromone, we investigated the pheromone response of olfactory antennal lobe (AL) interneurons in male A. ipsilon as a function of age and JH status by using intracellular recordings. When the antennae were stimulated with the sex pheromone blend, the sensitivity of olfactory AL neurons increased with age, as does the JH-dependent behavioral and physiological development of A. ipsilon males. Furthermore, males surgically deprived of JH showed a significant decrease in the sensitivity of the AL neurons. JH injection in operated or in young males restored or induced, respectively, a high sensitivity of the AL neurons. JH seems likely to be involved in the plasticity of the adult insect brain by modulating the central nervous processing of olfactory information, thus allowing mate recognition and reproduction at the optimal time.

Age Factors↗

PubMed1999

Integration of behaviourally relevant odours at the central nervous level in solitary and gregarious third instar locusts, Schistocerca gregaria.

Integration of behaviourally relevant odours at the central nervous level of 3rd instar nymphal desert locusts, Schistocerca gregaria, showed phase- and (developmental) stage-dependent characteristics which correlated with differences in the number of olfactory sensilla. Antennal lobe (AL) neurons of gregarious locusts generally responded more frequently and showed a higher sensitivity to the tested stimuli. However, AL neurons of solitary locusts responded significantly more frequently to phenylacetonitril, the major component of the adult aggregation pheromone. Pheromone-specific, plant-specific and pheromone-plant generalist neurons were found in both phases. The response spectra of pheromone-specific neurons correlated with the potential behavioural significance of attractant chemical cues in the environment. Neurons of both phases responded specifically to stage-specific aggregation-pheromone components and to other chemical cues that may be involved in the location of suitable roosting and foraging sites.

Journal Article↗

PubMed1998

Central processing of aggregation pheromones in solitary and gregarious desert locusts, Schistocerca gregaria.

In the desert locust, Schistocerca gregaria, a number of behaviorally active aggregation pheromone components have been identified from adult male S. gregaria, and from third, fourth and fifth instar nymphs. Adult females seem not to produce aggregation pheromones. Adult males and females, but not nymphs respond to the adult male-produced mixture, whereas only nymphs respond to the binary nymph-produced mixture with aggregation behavior. We studied the structure and function of antennal lobe interneurons, responding to single aggregation pheromone components and adult- and nymph-specific mixtures. Neurons in adult males and females and in first instar nymphs of S. gregaria in the solitary and the gregarious phase were investigated. Projection neurons responded with different degrees of specificity to all behaviorally active aggregation pheromone components. Component-specific, blend-specific and generalist neurons were found in adults and first instar nymphs in both phases. Antennal lobe neurons were slightly more sensitive in solitary than in gregarious locusts. In gregarious adult males and females more neurons responded to the adult male mix than to any of the single components. In gregarious first instar nymphs most neurons responded to the adult male mix and the major component but also nymph mix specific neurons were found. The behavior of adults and nymphs is thus partially reflected by the response characteristics of antennal lobe projection neurons.

Animal Communication↗

PubMed1998

Migraine therapy: development and testing of a patient preference questionnaire.

OBJECTIVES: To develop and test a patient preference questionnaire in migraine. METHODS: A user-friendly, self-administered questionnaire was developed to assess the relative importance of aspects of migraine therapy to patients. It was tested in a convenience sample of 66 migraineurs. The questionnaire has five sections: patient preference, migraine history, demographics, usual behavior during an attack, and migraine impact on cognition and functionality. It employs a special reverse-ranking technique to quantify preferences. RESULTS: Sixty-six migraineurs participated: 86% were women, 53% had not consulted their doctor about migraine in the previous year; and only 51% took prescribed medication, the majority (52%) at the start of a migraine. "A medication that can be taken any time during a migraine attack" was ranked most important by 20% of the migraineurs, one that decreases pain from the unbearable level in 30 minutes by 17%, and one that relieves pain completely within 2 hours by 15%. Not being able to think or concentrate with severe symptoms was reported by 71%. Optional activities were impeded by migraine in 83% of subjects, but required activities in only 60%. CONCLUSIONS: The patient preference questionnaire is readily completed by subjects and reveals that the dimensions of relief preferred by patients can be addressed by a self-report questionnaire.

Analgesics↗

PubMed1997

Central nervous processing of sex pheromones in two strains of the European corn borer Ostrinia nubilalis (Lepidoptera: Pyralidae)

Antennal lobe neurones were investigated in the pyralid moth Ostrinia nubilalis using intracellular recording and staining techniques. Response characteristics of antennal lobe neurones from males in the so-called E and Z strains, in F1 hybrids and in parental backcrosses were studied. The antennal lobe of a male O. nubilalis comprises approximately 30 ordinary glomeruli and three enlarged glomeruli making up the macroglomerular complex (MGC). Receptor neurones enter the antennal lobe via the antennal nerve and arborize in single glomeruli. Intracellularly stained, pheromone-responding projection neurones in both parental strains arborized in different glomeruli within the MGC, irrespective of their response characteristics. Neurones were grouped according to their specificity to single pheromone components and to pheromone blends. Component-specific, blend-specific and generalist neurones were found. Specificity only occurred at low stimulus concentrations and disappeared as concentrations increased. Although all neuronal types were present in both pheromone strains and crossings, differences in abundance and sensitivity were found. In the parental strains, neurones responding to the major pheromone component and to the respective strain-specific blend were more abundant than neurones responding to the minor component and the blend produced by the other strain. Neurones investigated in ZxE hybrids responded similarly to those of E-strain males, whereas neurones in EZxZ paternal backcrosses responded similarly to those of Z males. In the hybrids and paternal backcrosses, hybrid-blend-specific neurones were present that were not found in parental-strain males.

Journal Article↗

PubMed1997

[Social phobias].

Social phobia is an anxiety disorder which can be found in general and specific subtype in general population from 2.4 to 16%. People who are suffering from social phobia don't have opportunities for optimal development and their quality of life and work productivity is ruined too. Authors showed definition, diagnosis and differential diagnosis, epidemiology, clinical features, quality of life, work and social disability of people with social phobia. Biology and therapy of social phobia are also presented. This paper is based on findings around the world. Authors recommend more attention to social phobia, its specific type which is very rare, as much as one in comorbidity because this disorder can make big economic costs, especially through work disability, which can be changed by early treatment.

Humans↗

PubMed1996

Discrimination among pheromone component blends by interneurons in male antennal lobes of two populations of the turnip moth, Agrotis segetum.

A difference in female pheromone production and male behavioral response has previously been found in two populations of the turnip moth, Agrotis segetum, originating from Sweden and Zimbabwe, respectively. In this study, we investigated the pheromone response of antennal lobe interneurons of males of the two populations by intracellular recordings, stimulating with single pheromone components and various inter- and intra-populational pheromone blends. Three major physiological types of antennal lobe neurons were established in the two populations according to their responses to different stimuli. One type responded broadly to almost all the stimuli tested. The second type responded selectively to some of the single components and blends. The third type did not respond to any single components but did respond to certain blends. Furthermore, some neurons of the second and third type recognized strain specific differences in ratios between pheromone components. Both projection neurons and local interneurons were found among these three types. Two pheromone responding bilateral projection neurons are reported for the first time in this paper.

Animals↗

PubMed1996

Antennal lobe interneurons in the desert locust Schistocerca gregaria (Forskal): processing of aggregation pheromones in adult males and females.

Physiological and morphological characteristics of antennal lobe interneurons in male and female Schistocerca gregaria were studied by using intracellular recording and staining techniques. For the first time, the responses of projection neurons to behaviourally active and potential aggregation pheromone compounds and plant odour compounds were recorded in young adult locusts. Excitatory, inhibitory, or combined excitatory/inhibitory responses to the presented odours were detected. The stained neurons had their cell bodies in the frontal cell group, arborized in 10 to 25 glomeruli at equal distances from the central fibre core, and sent their axons to the calyces of the mushroom body and to the lateral protocerebrum. The projection neurons responded to the set of different stimuli with varying specificity. In females, more neurons responded specifically to single plant or aggregation pheromone compounds than in males, where more generalist responses were found. "Blend specialist" neurons, responding only to mixtures of behaviourally active aggregation pheromone compounds, but not to the single compounds, were present in both males and females. Most neurons responded to the behaviourally active aggregation pheromone mixtures and to single compounds present in these mixtures, as well as to plant odours. Fewer neurons responded to the potential aggregation pheromone compounds tested. In several experiments, two spike sizes in the recording were correlated with two stained neurons in the antennal lobe, suggesting electrical coupling of the neurons. No response to any of the stimuli was found in antennal lobe interneurons in old adults. The morphological and physiological features of the projection neurons in S. gregaria are compared with projection neuron characteristics in other insects.

Animals↗

PubMed1996

Central olfactory pathways in mosquitoes and other insects.

Studies of CNS processing of olfactory information have contributed significantly to understanding olfactory-guided behaviour in insects. Evidence in moths suggests that each glomerulus in the antennal lobes has a unique property: receptor-axon projections and dendritic arborizations of uniglomerular output neurons can relate to anatomically and functionally distinct glomeruli. Similar correlations are not typical of the concentrically organized locust antennal lobes. Insights about odour processing in the CNS of female mosquitoes should help us to understand how sensory information can lead to host-seeking behaviour. It will be interesting to learn how inputs from CO2 receptors on the maxillary palps and inputs from antennal olfactory receptors that respond to host odours are integrated centrally, so that pharmacological manipulation of olfactory neuron activity might provide a tool for the control of mosquitoes as important vector insects. The antennal lobe of male and female Aedes aegypti contains 20-25 glomeruli. Primary afferent projections from the antennae and maxillary palps target specific glomeruli of the ipsilateral antennal lobe. Maxillary palp projections are restricted to two posteromedial glomeruli, which do not receive antennal afferents. The latter arborize in the remaining glomeruli.

Animals↗

PubMed1994

Central processing of sex pheromone, host odour, and oviposition deterrent information by interneurons in the antennal lobe of female Spodoptera littoralis (Lepidoptera: Noctuidae).

Physiological and anatomical characteristics of antennal lobe interneurons in female Spodoptera littoralis (Boisd.) were investigated using intracellular recording and staining techniques. Responses of local interneurons and projection neurons to female sex pheromone components, host plant odours, and behaviourally active oviposition deterrents were recorded. We found local interneurons and projection neurons that responded specifically to only one or two of the tested odours, but we also found less specific cells, and neurons that responded to most of the tested odourants. These findings show that there are not only specific olfactory pathways in female moths up to the protocerebral level, but also that integration can begin in the antennal lobe. No correlation was found between the degree of specificity of either local interneurons or projection neurons and their respective morphological characteristics. Specialized and unspecialized local interneurons arborized throughout the antennal lobe. Specialized and unspecialized projection neurons had uniglomerular arborizations in the antennal lobe and sent their axons to the calyces of the mushroom body, and to the lateral horn of the protocerebrum. One specific projection neuron had multiglomerular arborizations and projected only to the lateral horn of the protocerebrum. Projection neurons arborizing in the glomeruli closest to the entrance of the antennal nerve always responded to pheromone components. No other correlations were found between the arborization pattern of projection neurons in the antennal lobe or in the protocerebrum and their response characteristics. The sensitivity of local interneurons and projection neurons was in the same range as that of receptor neurons in olfactory sensilla on the antennae, suggesting a much lower convergence in the central nervous system in females than in the pheromone-processing pathway in males.

Animals↗

PubMed1992

[Inpatient and partial hospitalization facilities for child and adolescent psychiatry in the unified Germany, 1991].

First results of the project "Surveys regarding the structure of psychiatric institutions for children and adolescents in the Federal Republic of Germany" are described. On July 1, 1991 there were 111 in-patient institutions with a total capacity for 6363 children and youths. The contributing shares of each state (Bundesland) vary enormously. The number of accommodations per 100,000 residents is between 2.1 and 19. One reason for this discrepancy lies in the fact that the services of the institutions are called upon without regard to the state borders. More important though is the fact that in the new states the psychiatric institutions for children and youths also treat young patients who are psychologically or mentally handicapped with neuropsychiatric complications to a greater extent than comparable institutions in the old states.

Adolescent↗